Collaboration Workshop on Cosmology and Galaxy Formation

Session

Dark Matter

Jun 19, 2023, 2:00 PM

3rd floor meeting room (SJTU & Suzhou Bay)

Conveners

Dark Matter: structure

• Houjun Mo (U. Mass.)

Dark Matter: nature

• Xi Kang (zhejiang university)

28. Iterative mean-field approach to the spherical collapse of dark matter haloes

Xun Shi

6/19/23, 2:00 PM

Model

Talk

Gravitational collapse of dark matter overdensities leads to the formation of dark matter haloes which embed galaxies and galaxy clusters. An intriguing feature of dark matter haloes is that their density profiles closely follow a universal form irrespective of the initial condition or the corresponding growth history. This represents a class of dynamical systems with emergent universalities....

48. The depletion radius of dark matter halo

Jiaxin Han (Shanghai Jiao Tong University)

6/19/23, 2:20 PM

Model

Talk

I will talk about different boundaries of a dark matter halo focusing on our recently proposed depletion boundary. I will explain its physics and measurements, and illustrate how this new boundary could help us to gain new insights into halo evolution and to provide much improved description of the cosmic structure.

20. A physical and concise halo model based on the depletion radius

义丰 周 (上海交通大学)

6/19/23, 2:40 PM

Model

Talk

We develop a self-consistent and accurate halo model by partitioning matter according to the depletion radii of haloes. Unlike conventional models that define haloes with the virial radius while relying on a separate exclusion radius or ad-hoc fixes to account for halo exclusion, our model distributes mass across all scales self-consistently. Using a cosmological simulation, we show that our...

51. On the formation process of dark matter deficient galaxies

Prof. Go Ogiya (Zhejiang University)

6/19/23, 3:00 PM

Model

Talk

Recent observations revealed that the dark matter mass contained in two ultra diffuse galaxies in the vicinity of an elliptical galaxy, NGC 1052, is several hundred times lower than the predictions by the theoretical models of galaxy formation and evolution. The dynamics of the galaxies is described by only the gravity of stars. As such dark matter deficient galaxies can be a challenge for the...

54. Modeling the formation of dark-matter deficient galaxies

Zhaozhou Li

6/19/23, 3:40 PM

Talk

Recent observations reported a puzzling dearth of dark matter (DM) in a fraction of massive high-z galaxies and dwarf galaxies, challenging current simulation predictions within the standard LCDM scenario. This discrepancy underscores our limited understanding of the driving forces behind the halo structural evolution, including feedback outflows, mergers, and tidal interaction. Here we...

40. Imprints of cosmic reionization as a probe of dark matter nature in the post-reionization era

Ms Yao Zhang (Tsinghua University)

6/19/23, 4:00 PM

Model

Talk

We propose a novel mechanism for constraining warm dark matter (WDM) models via the so-called “memory of reionization” effect, which is that gas in the intergalactic medium (IGM) after cosmic reionization can be affected significantly by inhomogeneous reionization of hydrogen. The suppression of small-scale structure due to WDM affects the evolution of post-reionization IGM, while thermal...

38. Model for Warm Dark Matter Subhalo Distribution

飞鸿 何 (上海交通大学物理与天文学院天文系)

6/19/23, 4:20 PM

Model

Talk

The unified distribution model of cold dark matter (CDM) subhaloes is extended to the warm dark matter (WDM) case using a series of high-resolution N-body simulations with different WDM particle masses. The same model framework combining the unevolved mass function, unevolved radial distribution and tidal stripping can predict the mass function and spatial distribution of subhaloes in both CDM...

4. A ~300 pc-sized core of Milky Way dark matter halo constrained from the OGLE micro-lensing sky map

Dr Wentao Luo (DSEL/USTC)

6/19/23, 4:40 PM

Galaxy Structure

Talk

We report the detection of a 282 $^{+34}_{-31}$ pc-sized dark matter core structure in the center of Milky Way at $68\%$ confidence level by using the micro-lensing event rate sky map data from the Optical Gravitational Lensing Experiment (OGLE) survey. For the first time, we apply the spacial information of the micro-lensing sky map and model it with the detailed Milky Way Dark Matter halo...